perf(checkout): reduce duplicate pricing refresh latency

[yan-ad]

Summary

• remove the extra classic checkout fee AJAX/update_checkout chain so native update_order_review renders fees in one path
• sync classic checkout payment, insurance, and force-insurance POST state before Woo fee calculation
• add bounded stale pricing fallback and keep shipping_price timeout safer at 10s with a filter override

Tests

• vendor/bin/paratest --configuration paratest.xml --filter CheckoutShippingPerformanceTest
• vendor/bin/paratest --configuration paratest.xml --filter classic_checkout_updated_checkout_handler_must_not_recalculate_fees_recursively
• vendor/bin/paratest --configuration paratest.xml --filter block_checkout_shipping_radio_click_syncs_wc_blocks_selected_rate_for_order_summary
• vendor/bin/paratest --configuration paratest.xml --filter admin_ajax_fee_refresh_preserves_selected_shipping_method_before_caching_fees
• vendor/bin/paratest --configuration paratest.xml --filter native_block_checkout_cod_fee_fallback_reads_all_store_api_payment_session_keys
• vendor/bin/paratest --configuration paratest.xml --filter PluginStructure
• make zip